Embolic protection systems

ABSTRACT

An embolic protection device comprising an expandable structure and a catheter. The catheter has a distal region and a working channel. The working channel has a working channel opening disposed in the distal region of the catheter, the working channel and the working channel opening are dimensioned to slideably receive an interventional device. The working channel has a distal region and at least a portion of the distal region of the working channel is disposed within the expandable structure. The expandable structure, when expanded in a first blood vessel, is able to stop blood flow through a second blood vessel and able to allow blood to flow through the first blood vessel. The working channel opening is able to be disposed to allow an interventional device to enter the second blood vessel.

This application is a continuation of U.S. application Ser. No.11/715,266, filed Mar. 7, 2007, now abandoned, which claims the benefitof U.S. Provisional Application No. 60/781,059, filed Mar. 10, 2006,entitled “Embolic Protection Systems”, the contents of each of which arehereby incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to embolic protection systems. Theseembolic protection systems are particularly well-suited for use inbranched blood vessels.

BACKGROUND OF THE INVENTION

Vessels are commonly treated to reduce or eliminate narrowings caused byarteriosclerotic disease. Interventional treatments can include use ofballoon angioplasty, stenting, thrombectomy, atherectomy, and otherprocedures. During treatment particulate debris can be generated at thetreatment site. Infarcts, strokes, and other major or minor adverseevents are caused when debris embolizes into vasculature distal to thetreatment site.

To prevent embolization of debris, embolic protection devices have beendeveloped. During a procedure such devices can be placed distal orproximal to the treatment site. Embolic protection devices can removeemboli from the bloodstream by filtering debris from blood, by occludingblood flow followed by aspiration of debris, or can cause blood flowreversal to effect removal of debris. The shape, length and othercharacteristics of an embolic protection device are typically chosenbased on the anatomical characteristics in the vicinity of the treatmentsite. However, some anatomies present specific challenges due to theanatomical shape or configuration. Known embolic protection devices aregenerally unsuitable for protection of vessels downstream of lesions ator near bifurcations because it is hard to protect both distal branches.Another challenging situation involves treatment of arterioscleroticdisease in branch vessels, for example at the ostium of renal arterieswithin the human body. Known embolic protection devices are generallyunsuitable for protection of vessels downstream of lesions at or nearthe main renal artery because the artery is short and divides downstreaminto three or more additional branch vessels.

Accordingly, a need exists for an embolic protection device that willprevent embolization of debris generated at treatment sites withinbranch vessels.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, an embolic protectiondevice comprises an expandable structure and a catheter having a lumen.The expandable structure is expanded in a vessel run and the catheter isdeployed in the vessel run and in or near the vessel branch. Theexpandable structure interrupts flow into the branch vessel and canpermit flow in the vessel run. The catheter provides access to thebranch vessel for treatment or diagnosis therein. The expandablestructure may be a balloon, a membrane, or other structure. The embolicprotection devices described herein are particularly well-suited for usein branched blood vessels, but they can also be used in straight bloodvessels.

The invention provides an embolic protection device comprising anexpandable structure and a catheter, the catheter having a distal regionand having a working channel dimensioned to slideably receive aninterventional device, the expandable structure being attached to thedistal region of the catheter, the expandable structure having anexpandable working channel extension and a working channel opening, theexpandable working channel extension having a proximal end and a distalend, the proximal end of the working channel extension being attached toa distal end of the working channel, the distal end of the workingchannel extension forming the working channel opening, the workingchannel opening being disposed proximate an exterior surface of theexpandable structure when the expandable structure is expanded, and theworking channel, working channel extension, and the working channelopening forming a continuous lumen. In one embodiment, the expandablestructure comprises a flow channel. In one embodiment, the expandablestructure has a generally cylindrical shape, and in another embodiment,the expandable structure has a generally tubular shape.

The invention provides a method for positioning an embolic protectiondevice within a patient's vasculature, the method comprising: providingan embolic protection device as described herein; advancing the embolicprotection device to a target site within the patient's vasculature; andexpanding the expandable structure within the patient's vasculature.

The invention provides an embolic protection device comprising anexpandable structure and a catheter, the catheter having a distal regionand having a working channel, the working channel having a workingchannel opening disposed in the distal region of the catheter, theworking channel and the working channel opening dimensioned to slideablyreceive an interventional device, the working channel having a distalregion, at least a portion of the distal region of the working channelbeing disposed within the expandable structure, the expandablestructure, when expanded in a first blood vessel, is able to stop bloodflow through a second blood vessel and able to allow blood to flowthrough the first blood vessel, and the working channel opening is ableto be disposed to allow an interventional device to enter the secondblood vessel.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings.

FIG. 1 illustrates conceptually a partial side view diagram of a vessel.

FIGS. 2A, 2B, and 2C illustrate conceptually partial cross-sectionaldiagrams of an embolic protection system in accordance with the presentinvention.

FIG. 2D illustrates conceptually an isometric diagram of an embolicprotection system in accordance with the present invention.

FIG. 2E illustrates conceptually a top view diagram of an embolicprotection system in accordance with the present invention.

FIGS. 3A and 3B illustrate conceptually side view diagrams of cathetersused in conjunction with an embolic protection system in accordance withthe present invention.

FIGS. 4A, 4B, 4C, and 4D illustrate conceptually cross-sectionaldiagrams of an embolic protection system in accordance with the presentinvention.

FIG. 4E illustrates conceptually an isometric diagram of an embolicprotection system in accordance with the present invention.

FIG. 4F illustrates conceptually a top view diagram of an embolicprotection system in accordance with the present invention.

FIGS. 5A and 5B illustrate conceptually side view diagrams of cathetersused in conjunction with an embolic protection system in accordance withthe present invention.

FIG. 5C illustrates conceptually a partial cross-sectional diagram ofcatheters used in conjunction with an embolic protection system inaccordance with the present invention.

FIG. 6A illustrates conceptually an isometric diagram of an embolicprotection system in accordance with the present invention.

FIGS. 6B, 6D, and 6E illustrate conceptually plan view diagrams ofcomponents of an embolic protection system in accordance with thepresent invention.

FIG. 6C illustrates conceptually a cross-sectional diagram of acomponent of an embolic protection system in accordance with the presentinvention.

FIGS. 7A, 7B, 7C, and 7D illustrate conceptually a method of using anembolic protection system in accordance with the present invention.

FIG. 8A illustrates conceptually an isometric diagram of an alternativeembodiment of an embolic protection system in accordance with thepresent invention.

FIG. 8B illustrates conceptually a cross-sectional diagram of acomponent of an embolic protection system in accordance with the presentinvention.

FIG. 9A illustrates conceptually an isometric diagram of an alternativeembodiment of an embolic protection system in accordance with thepresent invention.

FIG. 9B illustrates conceptually a cross-sectional diagram of acomponent of an embolic protection system in accordance with the presentinvention.

FIGS. 9C, 9D, 9E, and 9F illustrate conceptually side view orcross-sectional diagrams of components of an embolic protection systemin accordance with the present invention.

FIGS. 10A, 10B, 10C, and 10D illustrate conceptually a method of usingan embolic protection system in accordance with the present invention.

DETAILED DESCRIPTION

The terms “distal” and “proximal” as used herein refer to the relativeposition of the guidewire and catheters in a lumen. The most “proximal”point of the catheter is the end of the catheter extending outside thebody closest to the physician. The most “distal” point of the catheteris the end of the catheter placed farthest into a body lumen from theentrance site.

The invention provides an embolic protection device comprising anexpandable structure and a catheter, the catheter having a distal regionand having a working channel dimensioned to slideably receive aninterventional device, the expandable structure being attached to thedistal region of the catheter, the expandable structure having anexpandable working channel extension and a working channel opening, theexpandable working channel extension having a proximal end and a distalend, the proximal end of the working channel extension being attached toa distal end of the working channel, the distal end of the workingchannel extension forming the working channel opening, the workingchannel opening being disposed proximate an exterior surface of theexpandable structure when the expandable structure is expanded, and theworking channel, working channel extension, and the working channelopening forming a continuous lumen. In one embodiment, the expandablestructure comprises a flow channel. In one embodiment, the expandablestructure has a generally cylindrical shape, and in another embodiment,the expandable structure has a generally tubular shape.

In embodiments of the invention, the catheter has a longitudinal axisand when the expandable structure is expanded, the flow channel has across-sectional area in a plane normal to the longitudinal axis that is20 to 90 percent, 50 to 90 percent, or 75 to 90 percent of thecross-sectional area of the expandable structure. In one embodiment, theexpandable structure is an actively expanded structure such asinflatable balloon. In one embodiment, the expandable structure isself-expanding. In one embodiment, the expandable structure is a meshcovered by a membrane. In another embodiment, the expandable structureis a laser-cut, open mesh nitinol tube covered by a thin layer ofsilicone polymer.

In one embodiment of the invention, the expandable structure, whenexpanded in a first blood vessel, is able to stop blood flow through asecond blood vessel and able to allow blood to flow through the firstblood vessel, and the working channel opening is able to be disposed toallow an interventional device to enter the second blood vessel. In oneembodiment of the invention, the working channel extension and theworking channel meet at an angle of from 75 to 105 degrees, and inanother embodiment, the working channel extension and the workingchannel meet at an angle of approximately 90 degrees. In one embodiment,the catheter comprises a guidewire lumen.

In embodiments of the invention, the working channel has an internaldiameter of from 0.030 cm to 0.51 cm, 0.10 cm to 0.28 cm, 0.15 cm to0.24 cm, 0.23 cm, or 0.18 cm. In embodiments of the invention, the fullyexpanded working channel extension and the fully expanded workingchannel opening have an internal diameter of from 0.030 cm to 0.51 cm,0.10 cm to 0.28 cm, 0.15 cm to 0.24 cm, 0.23 cm, or 0.18 cm. In oneembodiment, one or more radiopaque marker bands are located near thedistal end of the working channel. In another embodiment, one or moreradiopaque marker bands are located near the distal end of the workingchannel extension. In one embodiment, the device further comprises aretractable sheath that can be placed over the expandable structure.

The invention provides a method for positioning an embolic protectiondevice within a patient's vasculature, the method comprising: providingan embolic protection device as described herein; advancing the embolicprotection device to a target site within the patient's vasculature; andexpanding the expandable structure within the patient's vasculature. Inone embodiment, the expandable structure is expanded in a first bloodvessel, and stops blood flow through a second blood vessel and allowsblood to flow through the first blood vessel, and the working channelopening is disposed to allow an interventional device to enter thesecond blood vessel. In another embodiment, a second catheter isintroduced into the working channel, working channel extension, andworking channel opening, and an interventional device is introduced intoa lumen of the second catheter. In one embodiment, an interventionaldevice is introduced into the second blood vessel and the blood in thesecond blood vessel is subsequently aspirated.

The invention provides an embolic protection device comprising anexpandable structure and a catheter, the catheter having a distal regionand having a working channel, the working channel having a workingchannel opening disposed in the distal region of the catheter, theworking channel and the working channel opening dimensioned to slideablyreceive an interventional device, the working channel having a distalregion, at least a portion of the distal region of the working channelbeing disposed within the expandable structure, the expandablestructure, when expanded in a first blood vessel, is able to stop bloodflow through a second blood vessel and able to allow blood to flowthrough the first blood vessel, and the working channel opening is ableto be disposed to allow an interventional device to enter the secondblood vessel. In one embodiment, the expandable structure comprises aflow channel. In another embodiment, the expandable structure has agenerally tubular shape.

In one embodiment, the expandable structure comprises two expandablerings joined by a membrane. In another embodiment, the expandablestructure is a mesh, the mesh having a portion covered by a membranethat prevents flow and having a portion not covered by a membrane soflow can occur through the mesh. This expandable structure may beself-expanding and the expandable structure may be a laser-cut, openmesh nitinol tube having a portion covered by a thin layer of siliconepolymer.

In one embodiment, the expandable structure has a distal portion and aproximal portion, and when the expandable structure is expanded thedistal portion is generally tubular and the proximal portion is tapered.In another embodiment, the expandable structure comprises three or moresealing arms, a membrane attached to the three or more sealing arms, andthree or more support arms. The sealing arms may be made ofself-expanding metal. The working channel opening may be disposed withinthe expandable structure. In one embodiment, the embolic protectiondevice further comprises a second catheter that can be introduced intothe working channel, working channel extension, and working channelopening, the second catheter having a lumen that can be used to deliveran interventional device.

In embodiments of the invention, the catheter has a longitudinal axisand when the expandable structure is expanded, the flow channel has across-sectional area in a plane normal to the longitudinal axis that is20 to 90 percent, 50 to 90 percent, or 75 to 90 percent of thecross-sectional area of the expandable structure. In one embodiment, theexpandable structure is an actively expanded structure such asinflatable balloon. In one embodiment, the expandable structure isself-expanding. In one embodiment, the expandable structure is a meshcovered by a membrane. In another embodiment, the expandable structureis a laser-cut, open mesh nitinol tube covered by a thin layer ofsilicone polymer. In one embodiment, the catheter comprises a guidewirelumen. In embodiments of the invention, the working channel has aninternal diameter of from 0.030 cm to 0.51 cm, 0.10 cm to 0.28 cm, 0.15cm to 0.24 cm, 0.23 cm, or 0.18 cm. In one embodiment, the devicefurther comprises a retractable sheath that can be placed over theexpandable structure.

FIG. 1 illustrates a partial side view diagram of vessel V in a body.Fluid flow travels through run R of vessel V. Branches B1 and B2 allowflow to divert from the flow direction F of the run so that flow canreach other parts of the body. Branch B1 is oriented at approximately 90degrees to (“normal to”) the run. Branch B2 is oriented at an angle tothe run. Branches oriented at an angle to the run are commonly referredto as having a superior takeoff or as having an inferior takeoff fromthe run depending on how they are oriented. The invention describedherein is suitable for use in vessels having branches with normal,inferior, or superior orientations to the run.

FIGS. 2A, 2B, 2C, 2D and 2E illustrate an embolic protection system inaccordance with the present invention. FIG. 2A shows embolic protectionsystem 10 comprised of expandable structure 12 and catheter 14 having aworking channel 16, inflation lumen 18, and optional guidewire lumen 19.Catheter 14 can be comprised of polymers including but not limited toPEBAX®, polyethylene, nylon, polyester, and other materials known in theart, and may be made by processes known by those skilled in the art,such as extrusion. Preferably catheter 14 is torquable and comprisesmetal reinforcement, for example braided wire. FIG. 2B illustrates across sectional view of the tip region of catheter 14 having optionalguidewire lumen 19. Guidewire lumen 19 is dimensioned to slideablyreceive guidewires (not shown) known in the art and can have an internaldiameter ranging from 0.009 inch to 0.040 inch (0.023 cm to 0.010 cm).In one preferred embodiment, guidewire lumen 19 has a diameter of 0.021inch (0.053 cm) and slideably receives 0.018 inch (0.046 cm) diameterguidewires. FIG. 2C illustrates a cross sectional view of the region ofcatheter 14 in the vicinity of expandable structure 12 having workingchannel 16, inflation lumen 18, and optional guidewire lumen 19. Workingchannel 16 is dimensioned to slideably receive interventional devicessuch as guidewires, balloon catheters, stent delivery systems withstents mounted thereon, atherectomy catheters, embolic protectiondevices such as distal embolic protection devices, thrombectomy devices,ultrasound catheters, aspiration catheters, and other devices (all notshown) known in that art and can have an internal diameter ranging from0.012 inch to 0.200 inch (0.030 cm to 0.51 cm), more preferably from0.040 inch to 0.110 inch (0.10 cm to 0.28 cm), more preferably from0.060 inch to 0.096 inch (0.15 to 0.24 cm). In one preferred embodiment,working channel 16 has a diameter of 0.092 inch (0.23 cm). In anotherpreferred embodiment, working channel 16 has a diameter of 0.070 inch(0.18 cm). A connector, for example a luer lock hub, may be attached tothe proximal end of working channel 16 (not shown). One or moreradiopaque marker bands 11 can be located on catheter 14 near the distalend of working channel 16. Radiopaque marker band 11 can compriseplatinum, gold, tantalum, or other materials known in the art.

FIG. 2A illustrates embolic protection system 10 in which expandablestructure 12 is unexpanded. FIG. 2D illustrates embolic protectionsystem 10 in which expandable structure is expanded and positioned invessel V having run R and branch B. Expandable structure 12 is comprisedof working channel extension 22, optional flow channel 24, and workingchannel opening 26. Working channel extension 22 is bonded to expandablestructure 12 at its distal most end 25 and is bonded to catheter 14 atits proximal most end 27 and may be comprised of a thin and strongmembranous material such as biaxially oriented nylon, polyester, PEBAX®,and the like. Working channel extension 22 and working channel opening26 are dimensioned to slideably receive interventional devices such asguidewires, balloon catheters, stent delivery systems with stentsmounted thereon, atherectomy catheters, embolic protection devices suchas distal embolic protection devices, thrombectomy devices, ultrasoundcatheters, aspiration catheters, and other devices (all not shown) knownin that art and can have an internal diameter ranging from 0.012 inch to0.200 inch (0.030 cm to 0.51 cm), more preferably from 0.040 inch to0.110 inch (0.10 cm to 0.28 cm), more preferably from 0.060 inch to0.096 inch (0.15 to 0.24 cm). In one preferred embodiment, workingchannel extension 22 has a diameter of 0.092 inch (0.23 cm). In anotherpreferred embodiment, working channel extension 22 has a diameter of0.070 inch (0.18 cm). One or more radiopaque marker bands 21 can belocated on working channel extension 22 or expandable structure 12 neardistal end of working channel extension 22. Radiopaque marker band 21can comprise platinum, gold, tantalum, or other materials known in theart. Optional flow channel 24 is dimensioned to permit flow F throughrun R of vessel V when expandable structure 12 is expanded. In a planenormal to the direction of flow in run R, the lumenal area of optionalflow channel 24 is preferably 20 to 90% of the run area in the sameplane. In a preferred embodiment, the lumenal area of optional flowchannel 24 is 50 to 90% of the run area. In a particularly preferredembodiment, the lumenal area of optional flow channel 24 is 75 to 90% ofthe run area.

Expandable structure 12 can be an inflatable balloon, a mesh covered bya membrane, or other structures and can be actively expanded, such as byexpanding a balloon, or can be self expanding. Expandable structure 12must remain in position when deployed and resist forces caused by flow Fin vessel V and may comprise anchors (not shown) on the surface ofexpandable structure 12 such as barbs, hooks, surface roughness, orother anchoring geometries as are known in the art. In one embodiment,expandable structure 12 is a self-expanding, laser cut, open meshnitinol tube covered with a thin membrane of silicone polymer andcatheter 14 comprises a retractable sheath (not shown) positioned overexpandable structure 12 so as to constrain expandable structure 12during system 10 delivery to vessel V. In one embodiment, expandablestructure 12 is an inflatable balloon and catheter 14 comprisesinflation lumen 18 as illustrated in FIGS. 2A and 2C and the proximalend of inflation lumen 18 comprises a connector, for example a luer lockhub (not shown). The inflatable balloon 12 may be comprised ofpolyethylene, polyester, nylon, PEBAX®, silicone, latex, urethane, orother materials as are known in the art and may be inflated usingsaline, radiographic contrast media, mixtures of saline and radiographiccontrast media, CO₂, or other fluids as are known in the art. In onepreferred embodiment, expandable structure 12 is a nylon twelve balloonand is inflated using a mixture of 75% saline and 25% radiographiccontrast media by volume.

FIG. 3A illustrates catheter 30 optionally used in conjunction withembolic protection system 10 in accordance with the present invention.Catheter 30 is comprised of hub 32, catheter shaft 34, and soft tip 36,and these three components are made of materials known in the art. Asexamples and not intended to be limiting, hub 32 may be comprised ofpolycarbonate or acrylic, catheter shaft 34 may be comprised of PEBAX®,polyethylene, nylon, or polyester, and soft tip 36 may be comprised ofPEBAX®, urethane, silicone, or EVA (ethyl vinyl acetate). Catheter 30 isdimensioned to be slideably received within working channel 16, workingchannel extension 22, and working channel opening 26 of system 10.Distal region 38 of catheter 30 may be curved as illustrated in FIG. 3Aand the exact curve will be chosen according to the intended use ofdevice 10. In a preferred embodiment, distal region 38 of catheter 30 iscomprised of a multipurpose curve as illustrated in FIG. 3A. In use,embolic protection system 10 is positioned in vessel V having branch Band catheter 30 is slideably advanced within working channel 16, workingchannel extension 22, and working channel opening 26 and positionedwithin or adjacent to branch B. Catheter 30 provides a smooth transitionbetween the junction of working channel 16 and working channel extension22 and in some embodiments reduces friction at this junction duringsubsequent advancement of interventional devices through system 10.

FIG. 3B illustrates catheter 40 optionally used in conjunction with anembolic protection system 10 in accordance with the present invention.Catheter 40 is comprised of handle 42, shaft 44, catheter shaft 34, softtip 36, and these four components are made of materials known in theart. As examples and not intended to be limiting, handle 42 may becomprised of polycarbonate or acrylic, shaft 44 may be comprised ofmetal, PEEK (polyetheretherketone), liquid crystal polymer, or polyamidewith or without metal reinforcement, and catheter 34 and soft tip 36 maybe comprised of materials as described above. Catheter 40 is dimensionedto be slideably received within working channel 16, working channelextension 22, and working channel opening 26 of system 10. Distal region38 of catheter 40 may be curved and the exact curve can be chosenaccording to the intended use of device 10. In some embodiments,catheter 40 distal region 38 is straight as shown in FIG. 3B. In useembolic protection system 10 is positioned in vessel V having branch Band catheter 40 is slideably advanced within working channel 16, workingchannel extension 22, and working channel opening 26 and positionedwithin or adjacent to branch B. Catheter 40 provides a smooth transitionbetween the junction of working channel 16 and working channel extension22 and in some embodiments reduces friction at this junction duringsubsequent advancement of interventional devices through system 10.

One non-limiting exemplary method of using embolic protection system 10in accordance with the present invention is now described. Embolicprotection system 10 is introduced into the arterial vasculature usingconventional techniques, advanced over a known guidewire and positionedin run R of vessel V opposite branch B. Position of catheter 14 isadjusted using images of marker bands 11, 21 as guides until workingchannel opening 26 is located at desired location such as oppositebranch B. To assist with positioning catheter 14, expandable structure12 may be partially expanded and a second guidewire may be advancedthrough working channel 16, working channel extension 22, and workingchannel opening 26 into branch B, and then catheter 14 advanced,retracted, or torqued until alignment between branch B and workingchannel opening 26 is achieved. Expandable structure 12 is then fullyexpanded, for example in the case where expandable structure 12 is aballoon, by inflation, until flow into branch B is interrupted asconfirmed by injection of radiographic contrast media through workingchannel 16, working channel extension 22, and working channel opening 26into branch B. The second guidewire is removed from system 10.

Optionally, catheter 30 or 40 is advanced through working channel 16,working channel extension 22, and working channel opening 26 into oradjacent to branch B. An interventional guidewire is advanced throughcatheter 30 or 40 (if used) and through working channel 16, workingchannel extension 22, and working channel opening 26 into or beyond theregion of interest of branch B, for example, distal to a lesion (notshown) in vessel branch B. Interventional devices such as angioplastyballoon catheters, stent delivery systems, and the like are advancedalong the interventional guidewire and used to treat the region ofinterest of branch B. Embolic debris generated during treatment, if any,remains in the vicinity of the treatment area because there is no flowin branch B to transport the embolic material from the treatment area.Interventional devices are then removed.

An aspiration device, for example a syringe, preferably at least 30 cccapacity, is used to draw a vacuum and aspirate emboli from the vicinityof the treatment area proximally through working channel opening 26,working channel extension 22, and working channel 16 into the aspirationdevice. Alternatively, aspiration device can be attached to hub ofcatheter 30 (if used) and emboli can be aspirated from the vicinity ofthe treatment area proximally through catheter 30. Catheter 30 may bemoved proximally and distally in the region of interest while aspirationis being applied to vacuum emboli from the region of interest.

After aspiration of emboli from the region of interest catheter 30 or 40(if used) can be removed, expandable structure 12 can be unexpanded, forexample in the case where expandable structure 12 is a balloon, bydeflation, thereby restoring flow into branch B, and embolic protectionsystem 10 can be removed from the patient.

In another non-limiting example, embolic protection system 10 can beused with a distal embolic protection device such as a filter or anocclusive device. After expansion of expandable structure 12, the distalembolic protection device is advanced through working channel 16 andthrough optional catheter 30 or 40 to a position distal to the region ofinterest, for example a stenotic lesion, in branch B, and then thedistal protection device is deployed. Emboli generated during crossingof the stenotic lesion by the distal protection device remains in thevicinity of the stenotic lesion because there is no flow in branch B totransport the embolic material from the stenotic lesion area.Optionally, expandable structure 12 is then unexpanded at least in part,restoring flow into branch B in the example where a distal embolicprotection filter is used. A distal embolic protection device such as afilter or an occlusive device can be used with any of the embodiments ofthe invention described herein.

In yet another non-limiting example, embolic protection system 10 can beused in conjunction with flow reversal techniques. After expansion ofexpandable structure 12, suction can be applied to the proximal end ofworking channel 16, to the proximal end of optional catheter 30 or 40,or to the proximal end of both, to cause blood to flow from branch Bretrograde through working channel 16, the lumen of optional catheter 30or 40, or both. The interventional procedure can then be performed andany emboli generated during the procedure will be transported by theretrograde flow proximally from the treatment site until removed fromthe body. Flow reversal techniques can be used with any of theembodiments of the invention described herein.

FIGS. 4A, 4B, 4C, 4D, and 4F illustrate an embolic protection system inaccordance with the present invention. FIG. 4A shows embolic protectionsystem 50 comprised of expandable structures 52 and catheter 54 having aworking channel 56, inflation lumen 58, and optional guidewire lumen 59.Catheter 54 can be comprised of polymers including but not limited toPEBAX®, polyethylene, nylon, polyester, and other materials known in theart, and may be made by processes known by those skilled in the art,such as extrusion. Preferably catheter 54 is torquable and is comprisedof metal reinforcement, for example braided wire. FIG. 4B illustrates across sectional view of the tip region of catheter 54 having optionalguidewire lumen 59. Guidewire lumen 59 is dimensioned to slideablyreceive guidewires (not shown) known in the art and can have an internaldiameter ranging from 0.009 inch to 0.040 inch (0.02 cm to 0.10 cm). Inone preferred embodiment, guidewire lumen 59 has a diameter of 0.021inch (0.053 cm) and slideably receives 0.018 inch (0.46 cm) diameterguidewires. The catheter tip optionally has depression 53 which is sizedto allow a guidewire (not shown) oriented parallel to the length ofcatheter 54 to fit into depression without increasing the overalloutside diameter of catheter 54. Depression 53 extends along outsidesurface of catheter 54 from distal end of opening 60 to tip of catheter54. FIG. 4C illustrates a cross sectional view of the region of catheter54 in the vicinity of opening 60 having inflation lumen 58 and optionalguidewire lumen 59. FIG. 4D illustrates a cross sectional view of theshaft region of catheter 54 having working channel 56, inflation lumen58, and optional guidewire lumen 59. Working channel 56 is dimensionedto slideably receive interventional devices such as guidewires, ballooncatheters, stent delivery systems with stents mounted thereon,atherectomy catheters, embolic protection devices such as distal embolicprotection devices, thrombectomy devices, ultrasound catheters,aspiration catheters, and other devices (all not shown) known in thatart and can have an internal diameter ranging from 0.012 inch to 0.200inch (0.030 cm to 0.51 cm), more preferably from 0.040 inch to 0.110inch (0.10 cm to 0.28 cm), more preferably from 0.060 inch to 0.096 inch(0.15 to 0.24 cm). In one preferred embodiment, working channel 56 has adiameter of 0.092 inch (0.23 cm). In another preferred embodiment,working channel 56 has a diameter of 0.070 inch (0.18 cm). A connector,for example a luer lock hub, may be attached to the proximal end ofworking channel 56 (not shown). One or more radiopaque marker bands 51can be located on catheter 54 near either or both ends of opening 60.Radiopaque marker band 51 can comprise platinum, gold, tantalum, orother materials known in the art.

FIG. 4A illustrates embolic protection system 50 in which expandablestructures 52 are unexpanded. FIG. 4E illustrates embolic protectionsystem 50 in which expandable structures 52 are expanded and positionedin vessel V having run R and branches B1 and B2. Expandable structures52 are comprised of optional flow channel 64 defined by membrane 62.Membrane 62 is permanently attached to expandable structures 52 at itsdistal most end 65 and at its proximal most end 67 and may be comprisedof a thin and strong membranous material such as biaxially orientednylon, polyester, PEBAX®, and the like. Optional flow channel 64 isdimensioned to permit flow F through run R of vessel V when expandablestructures 52 are expanded. In a plane normal to the direction of flowin run R, the lumenal area of optional flow channel 64 is preferably 20to 90% of the run area in the same plane. In a preferred embodiment, thelumenal area of optional flow channel 64 is 50 to 90% of the run area.In a particularly preferred embodiment, the lumenal area of optionalflow channel 64 is 75 to 90% of the run area.

Expandable structures 52 can be an inflatable balloon, a mesh covered bya membrane, or other structures and can be actively expanded, such as byexpanding a balloon, or can be self expanding. Expandable structures 52must remain in position when deployed and resist forces caused by flow Fin vessel V and may comprise anchors (not shown) on the surface ofexpandable structures 52 such as barbs, hooks, surface roughness, orother anchoring geometries as are known in the art. In one embodiment,expandable structures 52 are self-expanding, laser cut, open meshnitinol tubes covered with thin membranes of silicone polymer andcatheter 54 comprises a retractable sheath (not shown) positioned overexpandable structures 52 so as to constrain expandable structures 52during system 50 delivery to vessel V. In one embodiment, expandablestructures 52 are inflatable balloons, catheter 54 comprises inflationlumen 58 as illustrated in FIGS. 4A, 4C and 4D, and the proximal end ofinflation lumen 58 comprises a connector, for example a luer lock hub(not shown). The inflatable balloon 52 may be comprised of polyethylene,polyester, nylon, PEBAX®, silicone, latex, urethane, or other materialsas are known in the art and may be inflated using saline, radiographiccontrast media, mixtures of saline and radiographic contrast media, CO₂,or other fluids as are known in the art. In one preferred embodiment,expandable structures 52 are nylon twelve balloons and are inflatedusing a mixture of 75% saline and 25% radiographic contrast media byvolume.

FIGS. 5A and 5B illustrate catheters used in conjunction with an embolicprotection system in accordance with the present invention. Forconvenience expandable elements are shown in an unexpanded state inthese illustrations. It is understood that expandable elements 52 willpreferably be expanded during use of catheters 70 in conjunction withembolic protection system 50.

FIGS. 5A, 5B, and 5C illustrate catheter 70 inserted into catheter 52through working channel 56 and extending out of opening 60. Catheter 70may be an interventional catheter such as a guide catheter, ballooncatheter, stent delivery system with stent mounted thereon, atherectomycatheter, embolic protection device such as distal embolic protectiondevice, thrombectomy device, ultrasound catheter, aspiration catheter,or other device (all not shown) known in the art. Catheter 70 may be aninterventional catheter such as catheter 30 or catheter 40 describedpreviously in this document. In one preferred embodiment, catheter 70 isa steerable guide catheter. In another preferred embodiment, catheter 70is a non-steerable guide catheter. FIG. 5A shows catheter 70 orientedproperly 71 for use with a branch vessel having an inferior takeoff andin phantom shows catheter 70 oriented properly 72 for use with a branchvessel having an superior takeoff. FIG. 5B illustrates catheter 70oriented properly for use with a branch vessel having a normal takeoffand shows that the position of catheter 70 can be adjusted verticallybetween position 74 and phantom position 75 over vertical range ofmotion H. FIG. 5C illustrates that the position of catheter 70 can beadjusted angularly between position 77 and phantom position 78 overangular range of motion A. Embolic protection system 50 can be used witha broad range of vessel anatomies because the position of catheter 70can be adjusted relative to the orientation of branch vessels B so as tofacilitate passage of interventional catheters from working channel 56to lumen of branch B.

One non-limiting exemplary method of using embolic protection system 50in accordance with the present invention is now described. Embolicprotection system 50 is introduced into the arterial vasculature usingconventional techniques, advanced over a known guidewire and positionedin run R of vessel V opposite branch B2. Position of catheter 54 isadjusted using images of marker bands 51 as guides until opening 60 islocated at desired location such as opposite branch B2. To assist withpositioning catheter 54, expandable structures 52 may be partiallyexpanded and a second guidewire may be advanced through working channel56 into branch B2 and catheter 54 advanced, retracted, or torqued untilalignment between branch B2 and opening 60 is achieved. Expandablestructures 52 are then fully expanded, for example in the case whereexpandable structures 52 are balloons, by inflation, until flow intobranch B2 is interrupted as confirmed by injection of radiographiccontrast media through working channel 56 into branch B2. The secondguidewire is removed from system 50.

Optionally, catheter 70 is advanced through working channel 56 into oradjacent to branch B2. An interventional guidewire is advanced throughcatheter 70 into or beyond the region of interest within branch B2.Interventional devices such as angioplasty balloon catheters, stentdelivery systems, and the like are advanced along the interventionalguidewire and used to treat the region of interest within branch B2.Embolic debris generated during treatment, if any, remains in thevicinity of the treatment area because there is no flow in branch B2 totransport the embolic material from the treatment area. Interventionaldevices are removed after treatment.

An aspiration device, for example a syringe, preferably at least 30 cccapacity, is used to draw a vacuum and aspirate emboli from the vicinityof the treatment area proximally through working channel 56 into theaspiration device. Alternatively, aspiration device can be attached tohub of catheter 70 (if used) and emboli can be aspirated from thevicinity of the treatment area proximally through catheter 70. Catheter70 may be moved proximally and distally in the region of interest whileaspiration is being applied to vacuum emboli from the region ofinterest.

After aspiration of emboli from the region of interest, catheter 70 canbe removed, expandable structures 52 can be unexpanded, for example inthe case where expandable structures 52 comprise balloons, by deflation,thereby restoring flow into branch B2, and embolic protection system 50can be removed from the patient.

An alternative method of delivering embolic protection system 50 inaccordance with the present invention is now described. A guidewire isintroduced into branch B2 using conventional techniques. Embolicprotection system 50 is backloaded over the guidewire by inserting theproximal end of the guidewire into opening 60 and working channel 56 ofcatheter 54. The guidewire is pressed into depression 53 and introducedinto the arterial vasculature through a known introducer, and thenadvanced over the guidewire and positioned in run R of vessel V oppositebranch B2. If desired, a second guidewire can be loaded through optionalguidewire lumen 59 and the tip of second guidewire extended slightly outof distal end of catheter 54 tip to facilitate advancement of embolicprotection system 50 through the vasculature. The position of catheter54 is adjusted using images of marker bands 51 as guides until opening60 is located at desired location such as opposite branch B2. Expandablestructures 52 are then fully expanded until flow into branch B2 isinterrupted as confirmed by injection of radiographic contrast mediathrough working channel 56 into branch B2. The guidewire and secondguidewire may be removed from system 50.

FIGS. 6A, 6B, 6C, 6D, and 6E illustrate conceptually an alternativeembodiment of an embolic protection system in accordance with thepresent invention. FIG. 6A shows embolic protection system 80 comprisedof expandable structures 82, membrane 87, and catheter 84 having aworking channel 86, tether 88, and sheath 90. Catheter 84 can becomprised of polymers including but not limited to PEBAX®, polyethylene,nylon, polyester, and other materials known in the art, and may be madeby processes known by those skilled in the art, such as extrusion.Preferably catheter 84 is torquable and is comprised of metalreinforcement, for example braided wire. Working channel 86 isdimensioned to slideably receive interventional devices such asguidewires, balloon catheters, stent delivery systems with stentsmounted thereon, atherectomy catheters, embolic protection devices suchas distal embolic protection devices, thrombectomy devices, ultrasoundcatheters, aspiration catheters, and other devices (all not shown) knownin that art and can have an internal diameter ranging from 0.012 inch to0.200 inch (0.030 cm to 0.51 cm), more preferably from 0.040 inch to0.110 inch (0.10 cm to 0.28 cm), more preferably from 0.060 inch to0.096 inch (0.15 to 0.24 cm). In one preferred embodiment, workingchannel 86 has a diameter of 0.092 inch (0.23 cm). In another preferredembodiment, working channel 86 has a diameter of 0.070 inch (0.18 cm). Aconnector, for example a luer lock hub, may be attached to the proximalend of working channel 86 (not shown). One or more radiopaque markerbands 81 can be located on catheter 84 near distal end of workingchannel 86. Radiopaque marker band 81 can comprise platinum, gold,tantalum, or other materials known in the art. Tether 88 can becomprised of material having high tensile strength such as metal,suture, KEVLAR®, polyester, nylon, or other materials and may comprisemolecules oriented along the length of the tether. One preferredmaterial is stranded nitinol wire. Another preferred tether material isoriented DACRON® suture. Sheath 90 can be comprised of polymersincluding but not limited to PEBAX®, polyethylene, nylon, polyester, andother materials known in the art, and may be made by processes known bythose skilled in the art, such as extrusion. Preferably, sheath 90 istorqueable and is comprised of metal reinforcement, for example braidedwire. Sheath 90 is dimensioned to slideably receive catheter 84, tether88, expandable structure 82, and membrane 87.

Expandable structure 82 comprises rings 92 and flow channel 94 definedby membrane 87 and inner perimeter of rings 92. Membrane 87 ispermanently attached to rings 92 and to distal end of catheter 84 andmay be comprised of a thin and strong membranous material such asbiaxially oriented nylon, polyester, PEBAX®, and the like. Flow channel94 is dimensioned to permit flow F through run R of vessel V whenexpandable structure 82 is expanded. In a plane normal to the directionof flow in run R, the lumenal area of flow channel 94 is preferably 20to 90% of the run area in the same plane. In a preferred embodiment, thelumenal area of flow channel 94 is 50 to 90% of the run area. In aparticularly preferred embodiment, the lumenal area of flow channel 94is 75 to 90% of the run area.

Expandable structure 82 can be an elastic material pre-set in anexpanded shape, an elastic mesh, a laser cut, open mesh nitinol tube, orother structures and in a preferred embodiment are self-expanding.Expandable structure 82 must remain in position when deployed and resistforces caused by flow F in vessel V and may comprise anchors (not shown)on the surface of expandable structure 82 such as barbs, hooks, surfaceroughness, or other anchoring geometries as are known in the art. In oneembodiment, expandable structure 82 comprises rings 92 of superelasticnitinol wire of a circular cross section heat set into an expandedshape, illustrated in FIGS. 6B and 6C. In one embodiment, a ring 92comprises at least one beak 92 b formed into the structure (FIG. 6D),and in still another embodiment a ring 92 comprises at least one loop 92k formed into the structure (FIG. 6E). Beak 92 b and loop 92 kfacilitate folding of rings 92 so that they can be slideably receivedinto sheath 90.

With reference to FIGS. 7A, 7B, 7C, and 7D, a non-limiting exemplarymethod of using embolic protection system 80 in accordance with thepresent invention is now described. Embolic protection system 80 isintroduced into the arterial vasculature using conventional techniques,advanced through the vasculature and positioned in run R of vessel Vopposite branch B1. Position of sheath 90 is adjusted using images ofmarker band 81 as a guide until marker band 81 is located at desiredlocation such as superior to branch B1 (FIG. 7A). Distal most expandablestructure 82 is then expanded by withdrawing sheath 90 relative tocatheter 84 (FIG. 7B). Further withdrawal of sheath 90 relative tocatheter 84 exposes catheter tip (FIG. 7C). Catheter 84, sheath 90, orboth are then rotated by applying torsion on their respective shafts toassure that channel 86 is desirably aligned relative to branch B1.Radiographic contrast media can be injected through channel 86 tofurther ascertain orientation of catheter 84 tip relative to lumen ofbranch B1.

Once satisfied with orientation of catheter 84 tip relative to lumen ofbranch B1 sheath 90 is further withdrawn relative to catheter 84 untilthe proximal most portion of expandable structure 82 is expanded andtether 88 is fully outside of sheath 90 (FIG. 7D). When both distal mostand proximal most portions of expandable structure 82 are expanded, flowF in run R of vessel V is prevented from entering branch B1.

An interventional guidewire is now advanced through catheter 84 into orbeyond the region of interest of branch B1. Optionally, catheter 30, 40,or 70 is advanced through working channel 86 into or adjacent to branchB1 either before, during, or after advancement of the interventionalguidewire. Interventional devices such as angioplasty balloon catheters,stent delivery systems, and the like are advanced along theinterventional guidewire and used to treat the region of interest ofbranch B1. Embolic debris generated during treatment, if any, remains inthe vicinity of the treatment area because there is no flow in branch B1to transport the embolic material from the treatment area.Interventional devices are removed after treatment.

An aspiration device, for example a syringe, preferably at least 30 cccapacity, is used to draw a vacuum and aspirate emboli from the vicinityof the treatment area proximally through working channel 86 into theaspiration device. Alternatively, the aspiration device can be attachedto hub of catheter 30, 40, or 70 (if used) and emboli can be aspiratedfrom the vicinity of the treatment area proximally through catheter 30,40, or 70. Catheter 30, 40, or 70 may be moved proximally and distallyin the region of interest while aspiration is being applied to vacuumemboli from the region of interest.

After aspiration of emboli from the region of interest catheter 30, 40,or 70 can be removed, expandable structure 82 can be unexpanded byadvancing sheath 90 over catheter 84, causing tether 88 to enter sheath,followed by collapse of the proximal most portion of expandablestructure 82, membrane 87, and the distal most portion of expandablestructure 82. Optional beak or eyelets, if used, reduce the amount offorce needed to collapse expandable structure 82. Sheath 90 causes thecurvature of catheter 84 to be straightened as the catheter enters thesheath. As embolic protection system 80 is collapsed into sheath 90,flow into branch B1 is restored. Embolic protection system 80 canthereafter be removed from the patient.

FIGS. 8A and 8B illustrate an alternative embodiment of an embolicprotection system in accordance with the present invention. Embolicprotection system 100 is comprised of expandable structure 102 andcatheter 104 having working channel 106 and sheath 110. Catheter 104 canbe comprised of polymers including but not limited to PEBAX®,polyethylene, nylon, polyester, and other materials known in the art,and may be made by processes known by those skilled in the art, such asextrusion. Preferably catheter 104 is torquable and is comprised ofmetal reinforcement, for example braided wire. Working channel 106 isdimensioned to slideably receive interventional devices such asguidewires, balloon catheters, stent delivery systems with stentsmounted thereon, atherectomy catheters, embolic protection devices suchas distal embolic protection devices, thrombectomy devices, ultrasoundcatheters, aspiration catheters, and other devices (all not shown) knownin the art and can have an internal diameter ranging from 0.012 inch to0.200 inch (0.030 cm to 0.51 cm), more preferably from 0.040 inch to0.110 inch (0.10 cm to 0.28 cm), more preferably from 0.060 inch to0.096 inch (0.15 to 0.24 cm). In one preferred embodiment, workingchannel 106 has a diameter of 0.092 inch (0.23 cm). In another preferredembodiment, working channel 106 has a diameter of 0.070 inch (0.18 cm).A connector, for example a luer lock hub, may be attached to proximalend of working channel 106 (not shown). One or more radiopaque markerbands 101 can be located on catheter 104 near the distal end of workingchannel 106. Radiopaque marker band 101 can comprise platinum, gold,tantalum, or other materials known in the art. Sheath 110 can becomprised of polymers including but not limited to PEBAX®, polyethylene,nylon, polyester, and other materials known in the art, and may be madeby processes known by those skilled in the art, such as extrusion.Preferably sheath 110 is torqueable and is comprised of metalreinforcement, for example braided wire. Sheath 110 is dimensioned toslideably receive catheter 104 and expandable structure 102. Optionally,the distal portion of sheath 110 is keyed to catheter 104 by means of akey and keyway, linearly slideable non-circular cross sections, or othermeans (all not shown) to prevent the distal portion of sheath 110 fromrotating in relation to catheter 104.

Expandable structure 102 is comprised of mesh 111, membrane 112, andflow channel 115. Mesh 111 is attached to catheter 104 at location 116using techniques such as bonding, welding, fusing, solvent bonding,ultrasonic welding, and the like. Mesh openings 118 are dimensioned toallow flow of fluids through mesh, and mesh open area is defined as thecombined area of all mesh openings not apposed to wall of vessel V andnot covered by membrane 112 in the portion of mesh deployed outside ofsheath 110. Mesh 111 is preferably made of self-expanding metal such asELGILOY®, stainless steel, cobalt-chromium alloy, superelastic alloy,nitinol, or other materials as are known in the art. Mesh 111 may befabricated using techniques such as braiding of wires or filaments,knitting of wires or filaments, laser cutting of tubes, perforation ofsheet, welding of component parts, heat treatment, or other methods. Ina preferred embodiment, mesh 111 is comprised of braided nitinol wiresheat set in an expanded shape. Membrane 112 is permanently attached tomesh 111 and to distal end of catheter 104 and may be attached to outerdiameter of mesh, inner diameter of mesh, through the thickness of themesh, or any combination thereof. Membrane 112 is comprised of a thinand strong membranous material such as biaxially oriented nylon,polyester, PEBAX®, of thin flexible materials such as silicone,polyurethane, latex, and the like. In a preferred embodiment, membrane112 is comprised of silicone polymer of 90 Shore A durometer or less andis attached to the inner diameter of mesh 111. Membrane 112 may beattached to a portion of or to all of mesh 111. In a preferredembodiment, membrane 112 is attached to mesh in the region 114 extendingfrom near the tip of catheter 104 to a distance away from ostium O ofbranch B2 of vessel V. Flow channel 115 and mesh open area aredimensioned to permit flow F through run R of vessel V when expandablestructure 102 is expanded. In a plane normal to the direction of flow inrun R, the lumenal area of flow channel 115 is preferably 20 to 90% ofthe run area in the same plane. In a preferred embodiment, the lumenalarea of flow channel 115 is 50 to 90% of the run area. In a particularlypreferred embodiment, the lumenal area of flow channel 115 is 75 to 90%of the run area.

Expandable structure 102 must remain in position when deployed andresist forces caused by flow F in vessel V and may comprise anchors (notshown) on the surface of expandable structure 102 such as barbs, hooks,surface roughness, or other anchoring geometries as are known in theart. While expandable structure 102 is shown as a cylinder with aconical end in FIG. 8A, expandable structure 102 can have many shapeswithout departing from the spirit and scope of the invention. In oneembodiment, expandable structure 102 is made of superelastic nitinolwire of a circular cross section heat set into an expanded shape.

One non-limiting exemplary method of using embolic protection system 100in accordance with the present invention is now described. Embolicprotection system 100 is introduced into the arterial vasculature usingconventional techniques, advanced through the vasculature and positionedin run R of vessel V opposite branch B2. The position of system 100 isadjusted using images of marker band 101 as a guide until marker band101 is located at desired location such as superior to branch B2. Thedistal most portion of expandable structure 102 is then expanded bywithdrawing sheath 110 relative to catheter 104. Flow F will passthrough flow channel 115 including through mesh open area, allowingcatheter 104 to be more accurately positioned since there will be fewerflow generated forces altering the position of system 100. Furtherwithdrawal of sheath 110 relative to catheter 104 exposes the cathetertip. Catheter 104, sheath 110, or both are then rotated by applyingtorsion on their respective shafts to assure that working channel 106 isdesirably aligned relative to branch B2. Radiographic contrast media canbe injected through working lumen 106 to further ascertain orientationof catheter 104 tip relative to lumen of branch B2.

Once satisfied with the orientation of catheter 104 tip relative tolumen of branch B2, sheath 110 is further withdrawn relative to catheter104 until proximal portion of expandable structure 102 is expanded andfully outside of sheath 110, allowing membrane 112 to be pressed againstwall of vessel V. When both expandable structure 102 is expanded andmembrane 112 abuts vessel V in the region of ostium O of branch B2, flowF in run R of vessel V is prevented from entering branch B2.

An interventional guidewire is now advanced through catheter 104 into orbeyond the region of interest of branch B2. Optionally, catheter 30, 40,or 70 is advanced through working channel 106 into or adjacent to branchB2 either before, during, or after advancement of the interventionalguidewire. Interventional devices such as angioplasty balloon catheters,stent delivery systems, and the like are advanced along theinterventional guidewire and used to treat the region of interest ofbranch B2. Embolic debris generated during treatment, if any, remains inthe vicinity of the treatment area because there is no flow in branch B2to transport the embolic material from the treatment area.Interventional devices are removed after treatment.

An aspiration device, for example a syringe, preferably at least 30 cccapacity, is used to draw a vacuum and aspirate emboli from the vicinityof the treatment area proximally through working channel 106 into theaspiration device. Alternatively, the aspiration device can be attachedto the hub of catheter 30, 40, or 70 (if used) and emboli can beaspirated from the vicinity of the treatment area proximally throughcatheter 30, 40, or 70. Catheter 30, 40, or 70 may be moved proximallyand distally in the region of interest while aspiration is being appliedto vacuum emboli from the region of interest.

After aspiration of emboli from the region of interest, catheter 30, 40,or 70 can be removed, expandable structure 102 can be unexpanded byadvancing sheath 110 over catheter 104, causing expandable structure 102and catheter 104 to enter the sheath. Sheath 110 causes the curvature ofcatheter 104 to be straightened as catheter enters sheath. As embolicprotection system 100 is collapsed into sheath 110, flow into branch B2is restored. Embolic protection system 100 can thereafter be removedfrom the patient.

FIGS. 9A to 9F illustrate conceptually an alternative embodiment of anembolic protection system in accordance with the present invention.Embolic protection system 120 is comprised of expandable structure 122and catheter 124 having working channel 126 and sheath 130. Catheter 124can be comprised of polymers including but not limited to PEBAX®,polyethylene, nylon, polyester, and other materials known in the art,and may be made by processes known by those skilled in the art, such asextrusion. Preferably, catheter 124 is torquable and comprises metalreinforcement, for example braided wire. Working channel 126 isdimensioned to slideably receive interventional devices such asguidewires, balloon catheters, stent delivery systems with stentsmounted thereon, atherectomy catheters, embolic protection devices suchas distal embolic protection devices, thrombectomy devices, ultrasoundcatheters, aspiration catheters, and other devices (all not shown) knownin the art and can have an internal diameter ranging from 0.012 inch to0.200 inch (0.030 cm to 0.51 cm), more preferably from 0.040 inch to0.110 inch (0.10 cm to 0.28 cm), more preferably from 0.060 inch to0.096 inch (0.15 to 0.24 cm). In one preferred embodiment, workingchannel 126 has a diameter of 0.092 inch (0.23 cm). In another preferredembodiment, working channel 126 has a diameter of 0.070 inch (0.18 cm).A connector, for example a luer lock hub, may be attached to theproximal end of working channel 126 (not shown). One or more radiopaquemarker bands 121 can be located on catheter 124 near the distal end ofworking channel 126. Radiopaque marker band 121 can comprise platinum,gold, tantalum, or other materials known in the art. Sheath 130 can becomprised of polymers including but not limited to PEBAX®, polyethylene,nylon, polyester, and other materials known in the art, and may be madeby processes known by those skilled in the art, such as extrusion.Preferably sheath 130 is torqueable and comprises metal reinforcement,for example braided wire. Sheath 130 is dimensioned to slideably receivecatheter 124 and expandable structure 122. Optionally, the distalportion of sheath 130 is keyed to catheter 124 by means of a key andkeyway, linearly slideable non-circular cross sections, or other means(all not shown) to prevent the distal portion of sheath 130 fromrotating in relation to catheter 124.

Expandable structure 122 is comprised of three or more sealing arms 131,membrane 132, and three or more support arms 135. Sealing arms 131 areattached to catheter 124 at or near marker band 121 using techniquessuch as bonding, welding, fusing, solvent bonding, ultrasonic welding,and the like. Sealing arms 131 are preferably made of self-expandingmetal such as ELGILOY®, stainless steel, cobalt-chromium alloy,superelastic alloy, nitinol, or other materials as are known in the art.Sealing arms 131 may be wire, ribbon, sheet, composite, or othermaterials. In a preferred embodiment, sealing arms 131 are comprised ofmonofilament nitinol wires heat set in a curvilinear shape. Membrane 132is permanently attached to sealing arms 131 and may be attached to outersurface of arm, inner surface of arm, between arms, or any combinationthereof. Membrane 132 can be comprised of a thin and strong membranousmaterial such as biaxially oriented nylon, polyester, PEBAX®, of thinflexible materials such as silicone, polyurethane, latex, and the like.In a preferred embodiment, membrane 132 is comprised of silicone polymerof 90 Shore A durometer or less and is attached to the outer surface ofarm 131. Membrane 132 may be attached to a portion of or to all ofsealing arms 131. In a preferred embodiment, membrane 132 is attached tosealing arms 131 in the region extending from marker band 131 to thedistal tip of sealing arms 131. Support arms 135 are attached tocatheter 124 at or near marker band 121 using techniques such asbonding, welding, fusing, solvent bonding, ultrasonic welding, and thelike. In an alternative embodiment support arms 135 are attached tosealing arms 131. Support arms 135 are preferably made of self-expandingmetal such as ELGILOY®, stainless steel, cobalt-chromium alloy,superelastic alloy, nitinol, or other materials as are known in the art.Support arms 135 may be wire, ribbon, sheet, composite, or othermaterials. In a preferred embodiment, support arms 135 are comprised ofmonofilament nitinol wires heat set in a curvilinear shape.

Optionally, some or all of sealing arms 131, some or all of support arms135, or any combination thereof comprise pad 137 at the end thereof asshown in FIGS. 9C to 9F. Pad 137 distributes the force applied to vesselwalls from arms 131, 135 and prevents or reduces the potential damage tovessel V caused by the ends of arms 131, 135. Pad 137 can comprise aball 138 as shown in FIGS. 9C and 9D, can comprise a loop 139 as shownin FIGS. 9E and 9F, or can comprise other shapes provided the functionalrequirements of pad 137 are satisfied. Sealing arms 131 and support arms135 must remain in position when deployed and resist forces caused byflow F in vessel V and may comprise anchors (not shown) on the surfaceof pad 137 or at ends of arms 131, 135 such as barbs, hooks, surfaceroughness, or other anchoring geometries as are known in the art.

With reference to FIGS. 10A to 10D, one non-limiting exemplary method ofusing embolic protection system 120 in accordance with the presentinvention is now described. Embolic protection system 120 is introducedinto the arterial vasculature using conventional techniques, advancedthrough the vasculature and positioned in run R of vessel V oppositebranch B1. The position of system 120 is adjusted using images of markerband 121 as a guide until marker band 121 is located at a desiredlocation such as opposite branch B1 (FIG. 10A). The distal most portionof expandable structure 122 and sealing arms 131 are then expanded bywithdrawing sheath 130 relative to catheter 124 (FIG. 10B). Furtherwithdrawal of sheath 130 relative to catheter 124 exposes at least somesupport arms 135 (FIG. 10C). Flow F will pass by catheter 124 allowingthe catheter to be more accurately positioned since there will be fewflow generated forces altering the position of system 120. Catheter 124,sheath 130, or both are then rotated by applying torsion on theirrespective shafts to assure that channel 126 is desirably alignedrelative to branch B1. Radiographic contrast media can be injectedthrough channel 126 to further ascertain orientation of catheter 124 tiprelative to lumen of branch B1.

Once satisfied with orientation of catheter 124 tip relative to lumen ofbranch B1, sheath 130 is further withdrawn relative to catheter 124until the proximal portion of expandable structure 122 is expanded andsupport arms 135 are fully outside of sheath 130, allowing membrane 132to be pressed against the wall of vessel V (FIG. 10D). When bothexpandable structure 122 is expanded and membrane 132 abuts vessel V inregion of ostium O of branch B1, flow F in run R of vessel V isprevented from entering branch B1.

An interventional guidewire is now advanced through catheter 124 into orbeyond the region of interest of branch B1. Optionally, catheter 30, 40,or 70 is advanced through working channel 126 into or adjacent to branchB1 either before, during, or after advancement of the interventionalguidewire. Interventional devices such as angioplasty balloon catheters,stent delivery systems, and the like are advanced along theinterventional guidewire and used to treat the region of interest ofbranch B1. Embolic debris generated during treatment, if any, remains inthe vicinity of the treatment area because there is no flow in branch B1to transport the embolic material from the treatment area.Interventional devices are removed after treatment.

An aspiration device, for example a syringe, preferably at least 30 cccapacity, is used to draw a vacuum and aspirate emboli from the vicinityof the treatment area proximally through working channel 126 into theaspiration device. Alternatively, the aspiration device can be attachedto the hub of catheter 30, 40, or 70 (if used) and emboli can beaspirated from the vicinity of the treatment area proximally throughcatheter 30, 40, or 70. Catheter 30, 40, or 70 may be moved proximallyand distally in the region of interest while aspiration is being appliedto vacuum emboli from the region of interest.

After aspiration of emboli from the region of interest, catheter 30, 40,or 70 can be removed, expandable structure 122 can be unexpanded byadvancing sheath 130 over catheter 124, causing expandable structure 122and catheter 124 to enter the sheath. Sheath 130 causes the curvature ofcatheter 124 to be straightened and causes arms 131, 135 to bestraightened as they enter sheath 130. As embolic protection system 120is collapsed into sheath 130, flow into branch B1 is restored. Embolicprotection system 120 can thereafter be removed from the patient.

While this document has described an invention mainly in relation tovessel branch embolic protection, it is envisioned that the inventioncan be applied to other conduits in the body as well including arteries,veins, bronchi, ducts, ureters, urethra, and other lumens intended forthe passage of air, fluids, or solids. The invention can be applied toany site of branching of an artery, vein, bronchus, duct, ureter,urethra, and other lumen including but not limited to the junction ofthe common, internal, and external carotid arteries, the junction of themain, left anterior descending, and circumflex coronary arteries, thejunction of the left main or right coronary artery with the aorta, thejunction of the aorta with the subclavian artery, and the junction ofthe aorta with the carotid artery. The embolic protection devicesdescribed herein are particularly well-suited for use in branched bloodvessels, but they can also be used in straight blood vessels.

While the various embodiments of the present invention have related toembolic protection systems, the scope of the present invention is not solimited. Further, while choices for materials and configurations mayhave been described above with respect to certain embodiments, one ofordinary skill in the art will understand that the materials describedand configurations are applicable across the embodiments.

The above description and the drawings are provided for the purpose ofdescribing embodiments of the invention and are not intended to limitthe scope of the invention in any way. It will be apparent to thoseskilled in the art that various modifications and variations can be madewithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. An embolic protection device for use during asurgical procedure in treating a patient's vasculature including firstand second blood vessels intersecting one another at a juncture definingan ostium, the embolic protection device comprising: a catheter havingproximal and distal ends, the catheter defining an internal workingchannel in communication with a working channel opening formed in adistal region of the catheter, the working channel and the workingchannel opening dimensioned to slideably receive an interventionaldevice; a marker band supported by the catheter; and an expandablestructure supported on the distal region of the catheter, the expandablestructure comprising a sealing structure and a support structure, thesupport structure being connected to and extending proximally from themarker band such that the support structure is configured to contact thefirst blood vessel at a first location, and the sealing structure beingconnected to and extending distally from the marker band such that thesealing structure is configured to contact the first blood vessel at asecond location opposite the first location adjacent the ostium tointerfere with blood flow through the ostium, the working channelopening being configured and dimensioned to allow the interventionaldevice to enter the second blood vessel.
 2. The embolic protectiondevice of claim 1, wherein the working channel opening is disposedwithin the sealing structure.
 3. The embolic protection device of claim1, wherein the expandable structure is self-expanding.
 4. The embolicprotection device of claim 1, wherein the working channel has aninternal diameter of from 0.030 cm to 0.51 cm.
 5. The embolic protectiondevice of claim 1, wherein the working channel has an internal diameterof from 0.10 cm to 0.28 cm.
 6. The embolic protection device of claim 1,wherein the working channel has an internal diameter of from 0.15 cm to0.24 cm.
 7. The embolic protection device of claim 1, wherein the devicefurther comprises a retractable sheath that can be placed over theexpandable structure.
 8. The embolic protection device of claim 1,wherein the catheter has a curved distal portion.
 9. The embolicprotection device of claim 1, wherein the sealing structure is distal ofthe support structure.
 10. The embolic protection device of claim 1,wherein the marker band includes a radiopaque material.
 11. The embolicprotection device of claim 1, wherein the sealing structure comprisesthree or more sealing arms and a membrane attached to the three or moresealing arms, and the support structure comprises three or more supportarms.
 12. The embolic protection device of claim 11, wherein themembrane is made of silicone polymer.
 13. The embolic protection deviceof claim 11, wherein the sealing structure and the support structure areconnected to the catheter at locations spaced approximately equidistantfrom the working channel opening.
 14. The embolic protection device ofclaim 11, wherein the sealing structure is distal of the supportstructure.
 15. The embolic protection device of claim 11, wherein thesealing arms are made of self-expanding metal.
 16. The embolicprotection device of claim 15, wherein the support arms are made ofself-expanding metal.
 17. The embolic protection device of claim 11,wherein at least one of the sealing arms comprises a pad at an end ofthe sealing arm.
 18. The embolic protection device of claim 17, whereinthe pad comprises a ball.
 19. The embolic protection device of claim 17,wherein the pad comprises a loop.
 20. The embolic protection device ofclaim 11, wherein at least one of the support arms comprises a pad at anend of the support arm.
 21. The embolic protection device of claim 20,wherein the pad comprises a ball.
 22. The embolic protection device ofclaim 20, wherein the pad comprises a loop.
 23. A method for positioningan embolic protection device within a patient's vasculature, the methodcomprising: providing the embolic protection device of claim 1;advancing the embolic protection device to a target site within thepatient's vasculature; and expanding the expandable structure within thepatient's vasculature.
 24. The method of claim 23, wherein theexpandable structure is expanded in a first blood vessel, and stopsblood flow through a second blood vessel and allows blood to flowthrough the first blood vessel, and the working channel opening isdisposed to allow an interventional device to enter the second bloodvessel.
 25. The method of claim 24, wherein the interventional device isintroduced into the second blood vessel and the blood in the secondblood vessel is subsequently aspirated.